Elastic-fluid turbine.



E. THOMSON.

BLASTIG FLUID TURBINE'.

APPLIOATIQN FILED JULY a, 1907.

Wltmesses E. THOMSON.

.ELASTIG FLUID TURBINF APPLICATION FILED JULY 3, 1907.

Patented May 17, 1910.

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UNITED sTATEs PATENT AOFFICE.

'ELECTRIC COMPANY,

A CORPORATION F NEW YORK.

nLAsTrc-FLUID TURBINE.

To all whom it may concern:

1 3@ it known that I, ELrHU THOMSON, a citizen ofthe United States,residing at Swampscott, county of Essex, State of assachusetts, anduseful Improvements in Elastic-Fluid Turbines, of whichfthe following isa specifrom the theoretical angles,

phase type.

ication.

My invention relates to elastic fluid turbines, and has for its objectto improve their construction and at the saine time render them moreeflicient.

In carrying out my invention in its simplest form two oppositelyrotating bucketwheels contained in a casing are provided for the purposeof getting relatively high bucket-speed. In such a turbine as ordinailyconstructed the wheel acted upon directly by the steam or other motivefluid issuing from the nozzle or nozzles develops a materially greatertorque than does the second wheel which receives steam only after it haspassed through the irst wheel; To overcome this objection and obtainequal or sub'- stantially equal work from each wheel I provide two setsof nozzles, one set delivering directly t-o one wheel and the other setto the opposite, the steam exhausting from one wheel passing through'and acting on the buckets of the other. If, for any reason the y actualangles of the buckets and nozzles in such a combination have to vary toomuch I may use intermediate buckets between the wheel-buckets to insurethe proper relation. The wheels in such a. turbine have a tendency torevolve at Idifferent and varying speeds, whereas they should eitherrevolve at at the same speed or else one should revolve a certaindefinite percentage faster than the other. To connect the wheels forsuch operation electric generators are provided, one driven by eachwheel and these are connected electrically in such manner that theypreserve the speed relation. l

These generators may furnish alternatingcurrent, and, for example, be ofthe three- In this event the machines will be interconnected in theproper manner to make them assist each other in feeding the main lines.This constitutes an electrical gearing which takes the place of anymechanical gearing' and holds the turbines at proper speed.

For governing the turbine the yalve-chest Specification of LettersPatent. Application led July 3, 1907.

have invented certain. newl Patented May 1'7,v 1910. Serial No. 381,995.I

with advantage be located on one side of thewheel casing with parts orpassa es extending through the casing to the nozz'rles on the oppositeside of the wheels as well as to those cn the same side. The valves maybe actuated in a variety of ways. As an illustration, I have shown thevalves operated by cams through a ratchet and pawl mechanism that movesthe cam shaft forward or back in a step-b -step manner under the controlof a speed governor mounted on one of the turbine shafts. By preferencea valve admitting steam to one wheel will l iirst be opened or closed asthe case may be and then one to the other wheel, and so on. Since thewheels are compelled to run at the same speed by reason of theelectrical gearingone emergencyV governing mechanism will suiiice forbot-h and the emergency speed governor may advantageously be mounted onthe shaftthat does not support the ordinary speed governor. Theemergency gov- -ernor is so arranged that when the speed exceeds acertain predetermined `limit it releases a latch and lets a weight orother motor close the main throttle valve of the turbine and thus shutthe same down. I

I have referred to wheels having single rows of buckets, ideally simple,but wheels each greater number of rows of buckets employed. In bothcases mentioned the velocity of the steam will be abstracted bysuccessive fractions; but in the .latter case the number of operationswill be greater, and other things being equal a lower shaft speed may beobtained. l

In thefaccompanying drawings which are .illustrative of one embodimentof my invention, Figure l is a view partly in section of a turbine andtwo generators driven thereby; Fig. 2 is a plan view of the valvemechanisin with a portion in section; and Fig. 3 is a diagrammatic viewof the generator windings.

l indicates rthe bed-plate of the turbogenerator, and mounted thereonare two electric generators 2 and 3 of the alternating-current type, andthe casing 4 of the turbine, the latter being connected to a condenserby the conduit 5. Each generator is provided with its own shaft which 1sunited to one of the turbine shafts by the coupling 6. Each generatorshaft has its aving a may be own bearings carried by the generator cas-ving, and each turbine shaft has a bearing in the wheel casing withsuitable collars 7 to prevent axial movement of the bucketwheels. Thegenerators may be of any well known type and the rotating member may bethe field or the armature as best suits the requirements. On eachgenerator is a terminal board 8 carrying binding posts that areconnected to its windings and to the conductors 9, 10, and 11 forming apart of the electrical gearing. From these same conductors current issupplied to the outside lines and the translating devices. In certaincases it may be desirable to insert a transformer in these conductorsinstead of.

making them direct as shown.

Each wheel has a single row of buckets 12 and mechanically isindependent of the other. Steam or other elastic motive fluid isadmitted to the wheels by a set of nozzles 13 on one side of the turbineand by a set 14 on the other side. These nozzles may be expanding ornon-expanding in character as v pawls 22 and 23, one for moving therockshaft forward, the other for moving it backward. On one of thewheel-shafts is an eccentric surrounded by a strap 24 by means of whichand the connecting rod 25 the pawls and the arm carrying them areconstantly vibrated. Loosely mounted on the rock-shaft-is a second arm26 and this carries a shield-plate 27 The arm is connected by rods andbell-crank levers with the speed governor 28 mounted on the generatorshaft. The governor changes the position of the shield-plate withchanges in load, and said plate controls the action of the pawls on theratchet-wheel and therefore the position of the rock-shaft, cams andvalves.

Steam is admitted to the valve-chest by a throttle valve 29 which can beoperated by hand for starting and stopping the turbine or. by a weightunder emergency conditions.

`On thespindle of the valve is a drum and wound around the drum is awire rope or cord 30 having a weight 31 attached to one of its ends. Thethrottle-valve is normally kept from turning by means of a cord 32attached at one end to the drum or handwheel at one point and at theother end to a sliding rod 33. 4The end of the cord at- I tached to thehand-wheel is provided with a connector so arranged that the wheel canbe set to any desired position by hand to gire any desired opening ofthe throttle. The rod 33 is held in tension by 'the weight 31 and thecollar 311 on the rod engaging a stop 35 on the frame of the generator.Pivotally mounted on the generator is a lever 36 having a fork at thelower end engaging with the collar of a fly-ball emergency gov-.

ernor 37 mounted on the generator shaft. The other end is adapted toengage the rod 33, and release it from the stop 35 when the speed of theturbo-generator becomes abnormally higlnor, if desired, it could be setto trip the valve when the speed becomes abnormally low by propermodification. IVhen the sliding rod is released by being pushed upwardthe weight 31 overcomes the inertia o f the valve and its attachedparts, and closes it.

In Fig. 3 is shown diagrammatically two armatures connected by athree-phase connection to form an electrical gearing be- -tween the two.This connection does not necessarily feed the work circuit as in Fig. 1.In this case the rings 38 and 39 may be taken to indicate `the armaturesof directcurrent machines with the commutators and connections omitted.Instead of utilizing either alternating or direct-current machines, Imay use one alternating and one direct-current machine with a multiphaseconnection between, and take off alternatingcurrent single or multiphaseat one end of the machine and direct-current at the other.

It will be understood that the different sets of nozzles or the separatenozzle arcs on opposite sides of the pair of wheels are p'eripherallydisplaced with respect to each other so that there shall be nointerference by the f team moving one way with the steam moving from theopposite side. In fact, where the arc lcovered by the nozzles isextended the nozzles on opposite sides of the pair of wheels may be soplaced with respect to each other as to be diametrically opposite. Ifthe nozzle are for one wheel should cover an angle of approximately from120o to 180 this latter disposition would be of course" necessary.

In accordanceP with the provisions of the patent statutes, I havedescribed 'the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure byLetters Patent lof the UnitedStates, is,-

1. In an elastic'fluid turbine, the combinal tion of bucket-wheelsmounted `to revolve in opposite directions and receive motive Huid onefrom the other, nozzles arranged on opposite sides of the wheelstodischarge iuld through the wheels in opposite directions to las,equalize the torque thereof, electrical gear- `ing for causing theproper speed relation of the Wheels to be maintained, and a governingmechanism that is common to both Wheels. l v

2. In an elastic fluid turbine, the combination of bucket-Wheels mountedto revolve in opposite directions and receive motive fluid one from theother, nozzles disposed on opposite sides ofthe Wheels and'arranged insets, a valve-chest, passages extending from the valve-chest to the setsof nozzles, valves for varying the passage of fluid therethrough, and anactuating mechanism common to the valves.

3. Inan elastic fluid turbine, the combination of bucket-Wheels mountedto revolve in opposite `directions and receive motive fluid one 'fromthe other, nozzles disposed on `opposite y"sides of the Wheel andarranged in sets, a valve-chest, passages extending from the valve-chestto the sets of nozzles,

valves forfvarying the passage of fluid therethrough, an actuatingmechanism common to the valves, and electrical gearing for causing-theproper speed-relation of the wheels tobe maintained. v

4; In an elastic Huid turbine, the combination of bucket-Wheels mountedto revolve in opposite directions and receive motive iluid one from theother, nozzles disposed on opposite sides of the Wheel and arranged insets, a valve-chest located on one side of the Wheels, passagesextending from the valvechestto the sets of nozzles, valves for varyingthe passage .of fluid therethrough, an actuating mechanism common to thevalves, electrical gearing for causing the proper speed-relation of theWheels to be maintained, and a. governor responsive to the speed of theelectrically-geared Wheels for shutting oii the supply of motive iuidWhen the speed becomes abnormal.

In Witnesswhereot', I have hereunto set my hand this 28th day of June1907.

^ ELII-IU THGMSON, Witnesses JOHN A. McMANUs, Jr., CHARLES A. BARNARD.

